Boost Your Immunity: Essential Strategies for Surviving Cold and ‘Flu Season

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Vitamin C increases the production of infection-fighting white blood cells and antibodies and increases levels of interferon, the antibody that coats cell surfaces, preventing the entry of viruses

During cold and flu season, there are many things you can do to prevent and even treat infection. Personal hygiene is of paramount importance. Hand washing is the single most basic and important prevention against the spread of infection. Plain soap and water should be sufficient to protect against the spread of both viruses and bacteria.

There are also quite a few other proven strategies for boosting immunity in a safe and effective way.

The Immune Boosting Diet

Making simple changes to the diet can boost immunity dramatically. First, eliminate immune suppressors like sugar, refined carbohydrates, red meats, and processed foods. Eating foods laced with chemicals or those that are deficient in vitamins and minerals (e.g. empty calorie junk foods) increases the likelihood of catching viruses of any kind. Here are some helpful guidelines:

TO MINIMIZE SUGAR: Ease up on sodas, pastries, and such. You’ve probably had enough ice cream during the summer. A few grams of sugar can destroy your white blood cells’ ability to resist infections for several hours.

EAT FOR THE SEASON – Root vegetables, soups and slow-cooked stews and casseroles are all favorites for the fall and winter, as are beans and lentils. Don’t worry about calories (but avoid using too much fat and sugar in your cooking). Focus instead on the nutritional content. It’s normal to gain up to 4kg in the winter. This makes up part of your yin for the yang months.

EAT MORE GARLIC AND ONION: Besides being rich in antioxidants and selenium, garlic is antibacterial and antiviral. Both garlic and onions are part of the allium family, which is rich in sulfur-containing compounds responsible for many of their health promoting effects.

TAKE PROBIOTICS: Your body contains 10 times more bacteria than cells. Friendly bacteria not only attack pathogenic bacteria and fungi, but also trigger appropriate white cell reactions to invaders. They also positively influence your mental/emotional state. It’s estimated that 80 percent of your 100 trillion bacteria are located in the gut. Friendly bacteria are often depleted, especially by GMOs (the most widespread GMO foods are corn, soy, canola, and wheat). We all need probiotic foods and supplements. Commercial yogurt is insufficient. Raw milk and raw cheese, fermented foods, and water kefir, coconut kefire, or milk kefir should be staples. There are probiotic supplements as well, which deliver reliably high doses of multiple strains of good bacteria. (If you’re forced into taking antibiotics for an infection, double up on your probiotic supplements.)

• INCREASE VEGGIES, REDUCE OR ELIMINATE GRAINS: Eat lots of dark green vegetables, berries, nuts, fish, and lean organic meats like chicken along with a side of carrots, apples, and herbs of all kinds added to your plate. Avoid grain products and especially white bread. Grain contains gluten and anti-nutrients that make it hard to digest; it can even clog up your intestine, blocking absorption of vitamins and minerals.

Top Nutritional Supplements for Boosting Immunity

When people consider using natural remedies to boost their immune system, what typically first comes to mind are antioxidant vitamins and minerals. These include vitamins A, C, E, beta-carotene, glutathione, selenium, and zinc. Other popular choices are herbs, such as echinacea, whey protein concentrate, probiotics like Lactobacillus acidophilus and bovine colostrum.

Proven anti-viral remedies include oil of oregano, mild silver protein, thymus gland extracts, and medical ozone or hydrogen peroxide (intravenous, rectal insufflations or as an ozone steam bath).

There are also numerous anti-viral herbal remedies (see below). Different remedies work for different people. It’s all a matter of what suits your biochemistry best, as well as trial and error with different remedies or combinations. Work with a natural health care provider to create a personalized diet and supplement program.

Anti-Viral Herbs for Cold and Influenza

ANDROGRAPHIS  – in Scandinavia, this herb is used to fight the common cold, flu, and upper respiratory infections. It works by boosting the immune system, helping the body to battle infections and prevent them from reoccurring. Andrographis is also used to treat a host of illnesses in China, Thailand, and India – addressing bacterial and viral infections, fever, diarrhea, inflammation, blood pressure, and blood sugar problems. Andrographis tincture can be taken at the first sign of cold or flu symptoms, as a natural treatment.

ECHINACEA – has anti-bacterial and anti-viral properties; it is best used in combination with other anti-viral herbs during the course of flu season, as a preventive measure. It has a reputation as a blood purifier and also has interferon-like properties. It fights both strep and staph infections, candida (yeast infections) and can kill fungi. It has been used successfully for treating blood poisoning, ulcers, tuberculosis, childhood infections of every kind and a long list of skin, digestive and immune system disorders. Most herbalists recommend that echinacea be used on an intermittent basis (three weeks on, two weeks off) because its immune-boosting effects wane if used continuously. I do not agree with this. According to a growing number of herbalists like Canada’s Dr. Terry Willard, the on-off use of echinacea is unnecessary since studies indicate continued usage is best.


ELDERBERRY – extracts or syrups have been clinically proven to help people get over colds and influenza (a natural cure). It’s not a drug, so it’s cheaper and without the side effects that have been reported for Tamiflu.

LOMATIUM – contains anti-viral, anti-bacterial, and anti-inflammatory factors.

MYRRH GUM – is a gum resin with anti-microbial, anti-fungal, astringent, and expectorant properties. It stimulates white blood cell production.

PAU D’ARCO – is a herb that is well known for its antifungal properties and its stimulating effect on the immune system

ST. JOHN’S WORT– contains anti-viral and anti-inflammatory compounds, and was the focus of much AIDS research.

THUJA – has anti-viral, anti-fungal and expectorant properties  (induces release of phlegm from the lungs), effective in the treatment of warts, fungal infections, and bronchitis.

WILD INDIGO ­– contains alkaloids and oleo-resins which are anti-viral and anti-microbial.

Live Well – Make Yourself Strong

EXERCISE: Moderate exercise, even walking a mile or two at least three times a week, helps the lymph system cleanse impurities to boost your immune system. Avoid long gruelling workouts. A brisk walk every day is all you need in the winter. Mindful practices such as winter chi ball, qi gong, tai chi, yoga, Pilates and Feldenkrais are also excellent for building and balancing yin and yang.

REDUCE YOUR STRESS: This should be an all-year practice. Many consider stress or anxiety as the leading cause for decreased immunity. Lighten up. Try meditation or yoga. Laugh more. Be less critical. Worry less. Get counselling if needed to help you cope with stress or depression.

SLEEP: not necessarily more, but better. Make sure that where you sleep is totally dark so your melatonin production will be sufficient. There are melatonin supplements if you feel the need. The different phases of sleep contain two cycles that are deep enough to refurbish your immune system. You need to sleep through them.

Top 10 Immune Boosting Nutrients

Adequately feeding your immune system boosts its fighting power. Immune boosters work in many ways. They increase the number of white cells in the immune system army, train them to fight better, and help them form an overall better battle plan. Boosters also help to eliminate the deadwood in the army, substances that drag down the body. Here are the top 10 nutrients to add to your family’s diet; these will help cut down on days missed from work and school because of illness.

1 – VITAMIN C: This tops the list of immune boosters for many reasons. There has been more research about vitamin C than perhaps any other nutrient. Vitamin C supplements are inexpensive to produce, and the vitamin is present naturally in all fruits, garlic, and onions. Also, you can buy a vitamin C-fortified version of just about anything. Here’s what the research shows about how this mighty vitamin protects your body:

Vitamin C increases the production of infection-fighting white blood cells and antibodies and increases levels of interferon, the antibody that coats cell surfaces, preventing the entry of viruses. Vitamin C reduces the risk of cardiovascular disease by raising levels of HDL (good) cholesterol while lowering blood pressure and interfering with the process by which fat is converted to plaque in the arteries. As an added perk, persons whose diets are higher in vitamin C have lower rates of colon, prostate, and breast cancer.

If you take vitamin C supplements, space them throughout the day rather than take one large dose, most of which may end up being excreted in the urine. Doses that are effective for most healthy adults are 1,000 – 3,000 mg daily but individual needs at different times of life could be much higher.

2) COLOSTRUM – is the first mammary secretion nourishment that any mammal, including humans, provides for its newborn for the first 24-48 hours of life. It does not contain milk, as we know it. In choosing a bovine colostrum supplement, make sure it comes only from the first milking, ideally within the first 6 hours after birth of the calf. Choose your colostrum carefully as most brands combine the first milking (which is pure colostrum) with several subsequent milkings (which are mostly milk), resulting in products that more closely resemble milk or whey powder than true colostrum.

First milking colostrum contains numerous immune system and growth factors which trigger at least fifty processes in a newborn, ranging from the development of the immune system to the growth of all body cells. Laboratory analysis of immune and growth factors from bovine colostrum show them to be virtually identical to those found in human colostrum. And bovine colostrum is totally safe, with no known drug contraindications or negative side effects at any dosage level.

Conventional medical doctors were, at one time, enthusiastic about using colostrum for antibiotic purposes. This occurred prior to the introduction of sulfa drugs and penicillin. In the 1950s, prior to the widescale use of corticosteroids as anti-inflammatory agents, colostrum was used for the treatment of rheumatoid arthritis. Polio vaccine developer Dr. Albert Sabin discovered that colostrum contained antibodies against polio and recommended it for children susceptible to catching the disease. Bovine colostrum has been used therapeutically in India for thousands of years by Ayurvedic physicians, and still is to this day.

Well known colostrum components like interferon, gamma globulin, growth hormone (GH), IgF-1 and protease inhibitors are all used by conventional medical specialists in the treatment of cancer, chronic viral infections including HIV and autoimmune diseases. There are now over 4,000 clinical studies from around the world detailing research that has been done using colostrum in the treatment of dozens of different diseases.

First milking bovine colostrum is the ideal vaccination alternative. The reason is obvious when you look at its components. The two major components of colostrum are immune factors and growth factors. It’s the immune factors that offer the vaccine benefits. These include:

Immunoglobulins (A, D, E, G and M) – neutralize toxins, viruses and bacteria in the lymph and circulatory systems.

Lactoferrin – antiviral, anti-bacterial, anti-inflammatory, iron-binding protein with therapeutic effects in cancer, HIV, cytomegalovirus, herpes, chronic fatigue syndrome, candida albicans and other infections.

Proline-Rich Polypeptide (PRP) – a hormone that regulates the thymus gland, stimulating an underactive immune system or dampening an overactive immune system as seen in autoimmune disease (MS, rheumatoid arthritis, lupus, scleroderma, chronic fatigue syndrome, allergies, etc.).

Leukocytes – white blood cells that stimulate the production of interferon which slows viral reproduction and penetration of cell walls.

Enzymes – lactoperoxidase-thiocyanate, peroxidase and xanthine oxidase destroy bacteria through their ability to release hydrogen peroxide.

Lysozyme – a hydrolyzing agent and immune booster capable of destroying bacteria and viruses on contact.

Cytokines – interleukins that regulate the duration and intensity of the immune response, are responsible for cell to cell communication, boost T-cell activity and the production of immunoglobulins. Interleukin-10 is strongly anti-inflammatory, especially in arthritic joints.

Trypsin Inhibitors and Protease Inhibitors – prevent the destruction of immune and growth factors in colostrum from being broken down in the GI tract; they also prevent H. pylori from attaching to the walls of the stomach and can have a beneficial role in the treatment of peptic ulcers.

Lymphokines ­– hormone-like peptides produced by activated lymphocytes which mediate the immune response.

Oligo Polysaccharides and Glycoconjugates – attract and bind to pathogens (Strep., E. Coli, Salmonella, Cryptosporidia, Giardia, Entamoeba, Shigella, Clostridium Difficile Toxins A & B and Cholera), preventing them from attaching or entering the mucous membranes.

Other immune Factors – some of the documented immune factors include orotic acid, secretory IgA, IgA Specific Helper, B Lactoglobulin, Lactalbumin, Albumin, Prealbumin, Alpha 1-Antitripsin, Alpha 1-Fetoprotein, Alpha 2-macroglobulin, Alpha 2-AP Glycoprotein, C3, C4 and Orosomucoids.

Vitamins A, B12, and E are found in small amounts, while traces of all others are also present in colostrum.

Sulfur – a mineral with multiple uses in metabolism and as part of many structural body proteins.

If I had to choose one supplement to boost immunity and prevent the most common diseases for which conventional medicine recommends vaccines, colostrum would be my first choice.

3) VITAMIN E: This important antioxidant and immune booster doesn’t get as much press as vitamin C, yet it’s important to a healthy immune system.

Vitamin E stimulates the production of natural killer cells, those that seek out and destroy germs and cancer cells. Vitamin E enhances the production of B-cells, the immune cells that produce antibodies which destroy bacteria. Vitamin E supplementation may also reverse some of the decline in immune response commonly seen in aging.

Vitamin E has been linked to a lower risk of cardiovascular disease. In a Harvard School of Public Health study of 87,000 nurses, vitamin E supplementation was shown to cut the risk of heart attacks by 50 percent.

It’s not difficult to get 30 to 60 IU of vitamin E  every day from a diet rich in seeds, vegetable oils, and grains, but it’s difficult for most people to consume more than 60 IU a day consistently through diet alone. Supplements may be necessary to get enough vitamin E to boost your immune system.

You need 100-400 IU per day, depending on your general lifestyle. People who don’t exercise, who smoke, and who consume high amounts of alcoholic beverages will need the higher dosage. Those with a more moderate lifestyle can get by with lower levels of supplementation.

4? CAROTENOIDS: Beta-carotene increases the number of infection-fighting cells, natural killer cells, and helper T-cells, as well as being a powerful antioxidant that mops up excess free radicals which accelerate aging. Like the other “big three” antioxidants (selenium, vitamins C and E), beta-carotene reduces the risk of cardiovascular disease by interfering with how fats and cholesterol in the bloodstream oxidize to form arterial plaques. Studies have shown that it can lower the risk of cardiovascular disease, especially strokes and heart attacks, giving scientific credence to the belief that a carrot a day can keep the heart surgeon away.

It has also been shown that beta-carotene supplements can increase production of T-cell lymphocytes and natural killer cells and can enhance the ability of the natural killer cells to attack cancer cells. Beta-carotene is the most familiar carotenoid, but it is only one member of a large family. Researchers believe that it is not just beta-carotene that produces all these good effects, but all the carotenoids working together. This is why getting carotenoids in food may be more cancer-protective than taking beta-carotene supplements.

The body converts beta-carotene to vitamin A, which itself has anti-cancer properties and immune-boosting functions. But too much vitamin A can be toxic to the body, so it’s better to get extra beta-carotene from foods and let the body naturally regulate how much of this precursor is converted to the immune-enhancing vitamin A. It’s highly unlikely that a person could take in enough beta-carotene to produce a toxic amount of vitamin A, because when the body has enough vitamin A, it stops making it. The best food sources of beta carotene include pumpkins, squash, carrots, leafy greens, and cabbage.

5: VITAMIN D3: stimulates the production of proteins that act like natural antibiotics. Deficiency of vitamin D encourages infections, inflammation and immune system suppression. If you have adequate blood levels it is possible to prevent any and all infections. The trouble is that one has to get enough sunshine in order for the body to manufacture sufficient vitamin D through the action of ultraviolet light on the skin. This may be very difficult to achieve during the winter months in Canada. Hence, regular oral supplementation of emulsified vitamin D drops are almost mandatory. Check blood levels before supplementing with vitamin D. The optimal average adult dose is between 5000 and 10,000 IU daily. For more information on vitamin D, see my book, Vitamin D, The Sunshine Vitamin.

Boost Your Immune System

Acai berries aid the immune system by protecting the body’s cells against environmental pollutants

6: BIOFLAVONOIDS: A group of phytonutrients called bioflavonoids aid the immune system by protecting the cells of the body against environmental pollutants. Bioflavonoids protect cell membranes against the pollutants trying to attach to them. Along the membrane of each cell there are microscopic parking spaces, called receptor sites. Pollutants, toxins, or germs can park here and gradually eat their way into the membrane of the cell, but when bioflavonoids fill up these parking spots there is no room for toxins to park. Bioflavonoids also reduce cholesterol’s ability to form plaques in arteries, and lessen the formation of microscopic clots inside arteries which can lead to heart attack and stroke. Studies have shown that people who eat the most bioflavonoids have less cardiovascular disease. A diet that contains a wide variety of fruits and vegetables, at least six servings per day, will help you get the bioflavonoids needed to rev up your immune system so it’s working in top form.
(Ed. note: Superfoods contain the richest sources of bio-flavonoids including anthocyanins, quercetin, and hesperidin. Recommended are acai berries, maqui berries, goji berries, noni juice, black currants, and kale.)

7: ZINC: This valuable mineral increases the production of white blood cells that fight infection and helps them fight more aggressively. It also increases killer cells that fight against cancer and helps white cells release more antibodies. Zinc is an important mineral required by the body in the manufacture of proteins, especially those found in enzymes and numerous hormones, including insulin. Zinc increases the number of infection-fighting T-cells, especially in elderly people who are often deficient in zinc, and whose immune system often weakens with age.

The anti-infection hype around zinc is controversial. While some studies claim that zinc supplements in the form of lozenges can lower the incidence and severity of infections, other studies have failed to show this correlation. A word of caution: too much zinc in the form of supplements (more than 75 mg a day) can inhibit immune function. It’s safest to stick to getting zinc from your diet and aim for 15 to 25 milligrams a day. 
For infants and children, there is some evidence that dietary zinc supplements may reduce the incidence of acute respiratory infections, but this is controversial. The best source of zinc for infants and young children is zinc-fortified cereals.

8: GARLIC: This flavourful member of the onion family is a powerful immune booster that stimulates multiplication of infection-fighting white cells, boosts natural killer cell activity, and increases the efficiency of antibody production. The immune-boosting properties of garlic are due to its sulfur-containing compounds, such as allicin and sulfides. Garlic can also act as an antioxidant that reduces the build-up of free radicals in the bloodstream. Garlic may protect against cancer, though the evidence is controversial. Cultures with a garlic-rich diet have a lower incidence of intestinal cancer. It is also a heart-friendly food since it keeps platelets from sticking together and clogging tiny blood vessels.

9: SELENIUM: This mineral increases natural killer cells and mobilizes cancer-fighting cells. Best food sources of selenium are tuna, red snapper, lobster, shrimp, whole grains, vegetables (depending on the selenium content of the soil they’re grown in), brown rice, egg yolks, cottage cheese, chicken (white meat), sunflower seeds, garlic, Brazil nuts, and lamb chops.

Boost Your Immune System

Omega-3 fatty acids act as immune boosters by increasing white blood cells’ activity

10: OMEGA-3 FATTY ACIDS: One study found that children taking a half teaspoon of flax oil a day experienced fewer and less severe respiratory infections and fewer days of being absent from school. The omega-3 fatty acids in flax seed oil and fatty fish (such as salmon, tuna, and mackerel) act as immune boosters by increasing the activity of phagocytes, the white blood cells that eat up bacteria. (Perhaps this is why grandmothers used to insist on a daily dose of cod liver oil.) Essential fatty acids also protect the body against damage from over-reactions to infection. When taking essential fatty acid supplements, such as flax or fish oils, take additional vitamin E, which acts together with essential fatty acids to boost the immune system. One way to get more omega-3 fatty acids in your diet is to add one to three teaspoons of flax oil to a fruit and yogurt smoothie.

• Garlic: Nothing like good old-fashioned garlic to protect against seasonal infections. This ancient remedy has a long history going all the way back to traditional Asian medicine where it’s been used to alleviate many health problems. In Russia it was used just like an antibiotic, and even today it still makes a good alternative to antibiotics(1) and works to keep your immune system functioning properly while also protecting against inflammation and cardiovascular disease.

• Selenium: This all-important trace mineral is typically found in fish and nuts. It’s actually located right in the proteins of animal tissues and is called selenoprotein. It offers protection against infectious disease(2) as well as cancer. Selenium’s potential anti-cancer ability has been studied in clinical trials for many years, and the results have come back mostly positive. This is probably indirectly linked to the way it helps the immune system, which in turn helps to prevent cancer. It’s even been linked to an extended lifespan for people with with HIV/AIDS.(3)

You can supplement with at least 200 mcg a day, though as with any trace mineral you should be careful not to overdose. It’s even thought that selenium deficiency may have contributed to the polio outbreaks of the 1950s.(4)

Vitamin C: This vitamin is a tried and true way to prevent infections from happening. It was first isolated in the 1930s and has gone on to be a good remedy for heart disease, gout, cataracts, cancer, and immune function. It does this by increasing levels of serum antibodies that stimulate and protect the cells of the immune system. Good sources of this vitamin include camu berries, red peppers, wild rosehips, oranges, grapefruit, tomato, and broccoli.(5)

• Probiotics: Probiotics work by keeping the good bacteria well-populated in your intestines(6). These probiotics are found in foods like yogurt, buttermilk or kefir. They not only help boost immunity but aid in optimal digestion. Because the immune system is located so near to the intestine, this “good” bacteria also helps to fight off the “bad” bacteria. These same good bacteria also help to break down and absorb nutrients that can prevent infections, too. The good bacteria typically found in probiotics are acidophilus, bifidobacterium, and lactobacillus.

• Echinacea (Echinacea augustifolia) has a reputation as a blood purifier and also has interferon-like properties. It fights both strep and staph infections, candida (yeast infections) and can kill fungi. It has been used successfully for blood poisoning, ulcers, tuberculosis, childhood infections of every kind and a long list of skin, digestive and immune system disorders. Most herbalists recommend that echinacea be used on an intermittent basis (three weeks on, two weeks off) because its immune-boosting effects wane if used continuously. I do not agree with this. According to a growing number of herbalists like Canada’s Dr. Terry Willard, the on-off use of echinacea is unnecessary since studies indicate continued usage is best.

• Tea Tree Essential Oil: This wonderful-smelling oil has an amazing ability to prevent infections simply by breathing it in every day or adding it to your aromatherapy bath where its absorbed through the skin into the bloodstream. It was used for centuries by the Aborigines of Australia to help with infections.(7) Today it is still used as a broad spectrum anti-viral oil.

Mushrooms: Shittake mushroom is full of iron, vitamin C, protein, selenium, vitamin B3 and makes a good source of daily fibre. And it also holds a popular place in history as a great anti-viral and anti-bacterial that fights the problem at its source. The active compound responsible for this action is called lentinan.(8) The shiitake mushroom is also useful in preventing and fighting against cancer. Reishi mushroom is a medicinal mushroom containing polysaccharides with anti-tumour and immune-stimulating properties for the spleen and bone marrow. Medicinal Mushrooms, such as Reishi, Maitake and Shiitake stimulate many aspects of the immune system, including the production of interferon

Colloidal Silver: This tasteless liquid that originates from silver is good for killing bacteria, but it also destroys bad bacteria so it’s helpful to supplement with a probiotic or yogurt when taking colloidal silver. It works by the small colloids using electromagnetic to draw dead cells into the bloodstream where they are eliminated.(9)

Astragalus is a Chinese herb that enhances antibody reaction to antigens, increases T-lymphocyte activity, improves symptoms of many HIV-related problems and increases the body’s production of interferon. In traditional Chinese medicine, astragalus enjoys a long history of use as an immune system booster and potent tonic for increasing energy levels. Astragalus has been proven to enhance immunity in cancer patients and offsets bone marrow suppression and gastrointestinal toxicity caused by chemotherapy and radiation. No side effects have been reported.

Homeopathic Vaccines: Aside from vitamins, minerals and herbs, there are homeopathic vaccines that have been gaining popularity. Homeopathic specialists are best to consult for that approach. Doses for all other immune boosters should be individualized, ideally with the help of a natural health care provider such as a naturopath or complementary medical practitioner.


  • Clark, Daniel G. and Wyatt, Kaye. Colostrum, Life’s First Food. Salt Lake City:CNR Publications. 1996.
  • Heinerman, John. Dr. Heinerman’s Encyclopedia of Anti-Aging Remedies. Paramus:Prentice Hall, 1997; pp.85-86.
  • Jensen, Bernard. Colostrum: Man’s First Food, The White Gold Discovery. Escondido:Bernard Jensen, 1993.
  • Rona, Zoltan, P. Bovine colostrum emerges as immune system modulator. Am. Journal of Natural Medicine; March, 1998, pp. 19-23.
  • Rona, Zoltan, P. Natural Alternatives to Vaccination. Vancouver: Alive Books. 2000.


Zoltan P. Rona, MD, MSc, offers consultations on nutrition and natural remedies in Thornhill. He has recently retired from medical practice as a Complementary and Alternative medical practitioner and now strictly offers nutritional consultations. He is the medical editor of The Encyclopedia of Natural Healing and has also published several Canadian bestselling books, including Vitamin D, The Sunshine Vitamin. To see more of Dr. Rona’s articles, visit: and for appointments, please call (905) 764-8700; office located at: 390 Steeles Ave. W., Unit 19, Thornhill, Ontario

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